Sarepta Reaffirms Commitment to Eteplirsen, Other DMD Drugs

In a Dec. 2, 2014, webcast for the Duchenne MD community, Sarepta Therapeutics explains plans, answers questions; the presentation is available on Sarepta's site

Article Highlights:

Sarepta Therapeutics says it remains firmly committed to developing eteplirsen and other drugs in its pipeline for Duchenne muscular dystrophy.

The U.S. Food and Drug Administration's request for additional data on eteplirsen has delayed Sarepta's planned submission of a new drug application for this drug by about six months.

A phase 3 (confirmatory) trial of eteplirsen is underway and is open to new participants; in addition, a phase 2 study of the drug is underway in nonambulatory boys, and a phase 2 study of the drug in boys 4-6 years old is planned.

The presentation was made by Sarepta's president and CEO Chris Garabedian and Ed Kaye, the company's senior vice president and chief medical officer; it emphasized what Garabedian called the company's "unwavering goal of pursuing approval of eteplirsen."

After the formal webcast, Garabedian and Kaye answered questions from members of several DMD organizations, including MDA, which was represented by Grace Pavlath, senior vice president and scientific program director. The questioners, speaking for families affected by DMD, expressed concern about an October request from the U.S. Food and Drug Administration (FDA) for more data, delaying Sarepta's submission of a new drug application (NDA) for eteplirsen until mid-2015 instead of late 2014. They also expressed concern about Sarepta's commitment to developing additional exon-skipping compounds to treat DMD.

(In a late October statement, the FDA explained its position regarding a request for additional data on eteplirsen, noting that the agency "understands the dire urgency of the situation and the importance of our actions to the DMD community" and stating its intention to continue to work with Sarepta so that the company can provide the data the FDA considers crucial to an NDA.)

Sarepta is also conducting a phase 2 study of eteplirsen in nonambulatory boys ages 7-21 (see Safety Study of Eteplirsen to Treat Advanced Stage DMD or enter NCT02286947 in the search box at ClinicalTrials.gov) and plans to open a phase 2 study of the drug in boys 4-6 years old.

The submission of an NDA for eteplirsen will be delayed by about six months from its original 2014 goal.

Sarepta understands the desire of the FDA to have as much additional information as possible and wants to honor the agency's requests, with the goal of creating as strong an application for eteplirsen as possible.

Sarepta will not be able to meet requests for expanded access (sometimes called "compassionate use") for eteplirsen because the company will need to focus all resources on obtaining approval for the drug; the amount of drug they are able to make is going toward the clinical trials that will lead to the submission for approval.

Sarepta is not only developing eteplirsen as planned, but it is also developing exon-skipping drugs targeting other parts (exons) of the dystrophin gene. Compounds targeting exons 45 and 53 are in clinical trials, and additional compounds are in preclinical development.

Sarepta hopes for an eventual approval of several DMD exon-skipping drugs as a class.

The company is encouraged by new data that support the methods it is using to measure dystrophin – the protein missing in DMD – in muscle biopsy samples; eteplirsen and other exon-skipping drugs for DMD are designed to increase functional dystrophin levels in muscle fibers.

Sarepta is pursuing approval of eteplirsen and other compounds in its pipeline with European, as well as U.S., regulators.

"We continue to hear your urgency," said Garabedian in his closing remarks. "We assure you that it underpins all our activities here. At any moment that Ed [Kaye] or I see a softening of that urgency, we have many reasons to remind us that every day, week and month matters in getting this drug to patients."